There are many instances in the distribution of goods where different sizes and shapes of packaging cases, such as cardboard boxes, are presented for closure and sealing. In the past it has been relatively slow and difficult to accommodate these randomly sized cases using a single machine. This is due in part to the adjustments that must be made between differently sized cases being closed and sealed in a serial manner.
In many instances, the desired method of sealing is using an adhesively faced tape applied to the case after the flaps have been folded down. Adhesive tape sealing is often used where the cases or cartons are made of corrugated cardboard. The application of adhesively faced tapes has special challenges and requires different handling than other closure techniques due in part to the particularities of presenting and applying the thin, flexible adhesive tape stock. Having the tape be applied so that it is smooth and relatively tight presents special problems and considerations.
Another problem in the handling and sealing of randomly sized cases is the need to reposition the operative parts of the machine for each box or case. Varying heights of cases require elevational changes for both the closing and sealing stages. The size of the major flaps depends on the width of the cases which have associated varying flap widths. The randomly sized cases must be closed reliably even though both the height and width may vary over the total acceptable size range capability between two successive cases.
The sealing tape used on many cases must also be applied smoothly and evenly although the mechanism accomplishing this may be adjusted for each case being processed. To do this and maintain a high rate of throughput is a great challenge. The frequent positioning adjustments also tend to increase maintenance costs because of the accelerations and forces developed in the machine due to such frequent positioning changes which are desirably accomplished at high speeds.
Prior random case closing and sealing apparatus have in general operated slowly thus requiring more machines to process the same throughput of cases per time period. Since the machines have a significant cost, increasing the throughput while still providing reliable closure and sealing of randomly sized cartons without shutdowns is a significant advancement and represents significant economic savings.
The current invention addresses one or more of these problems and challenges using a number of features that provide improved processing of packaging cases which have major and minor flaps that are closed and then sealed, particularly when using an adhesively faced sealing tape.